`Rev.
ECO
A
32-129
Description
Initial Release
Author
B. Klatt
Approved
Date
5/18/06
CRaTER
Preliminary Hazard Analysis
Dwg. No. 32-04015
Revision A
May 18, 2006
Preliminary Hazard Analysis
The CRaTER Instrument is designed to characterize the global lunar radiation environment and its
biological impacts. Hardware is composed of six (6) silicon detectors, six (6) analog measurement
chains, eight (8) analog to digital converters, digital processing, standard housekeeping, DC to DC power
conversion, high voltage bias generation, telemetry, a telescope housing and an electronics enclosure.
Mission Assurance has performed a Hazard Analysis and identified three (3) potential hazards.

Pressure Vessel

High Voltage for detector bias voltage

Ionizing Radiation
a dry nitrogen purge bottle
radioactive source for test
Preliminary Hazard Analysis is Contract Data Requirements List (CDRL), item number 7.
PAYLOAD HAZARD REPORT
Payload
No.
CR 01
Phase
CRaTER Instrument on LRO
Subsystem
Ground Support Equipment
Hazard Group
Pressure Vessel
0
Date
5/18/06
Hazard Title
Nitrogen Purge Bottle
Applicable Safety Requirement
Hazard Category
Catastrophic
X Critical
Description of Hazard
Silicon Detectors in the CRaTER telescope are not hermetically sealed and need environmental Protection. After
telescope assembly, the telescope interior is periodically purged with dry nitrogen. The dry nitrogen is under
pressure in a steel cylindrical bottle.
Hazard Cause
Dry nitrogen must be kept under pressure to prevent evaporation.
Hazard Controls
Gas is purchased in OSHA approved and tested cylinders
Gas cylinders are not provided with flight hardware. After CRaTER delivery, purge must be provided by NASA
until launch.
Safety Verification Methods
Status of Verification
Approval
Payload organization
Boston University-CSP
Phase I
Phase II
Phase III
JSC Form 542B
PAYLOAD HAZARD REPORT
Payload
No.
CR 02
Phase
CRaTER Instrument on LRO
Subsystem
Hazard Group
Digital Electronic Assembly
High Voltage
0
Date
5/18/06
Hazard Title
Detector Bias Voltage
Applicable Safety Requirement
Hazard Category
Catastrophic
Critical
Description of Hazard
Silicon Detectors in the CRaTER telescope require high voltage for proper operation. A bias of 225 VDC and
75VDC is produced in the electronics assembly from 5 VDC by a DC-to-DC conversion.
Hazard Cause
Telescope detectors require bias voltage greater than 50 volts.
Hazard Controls
The bias voltage is fed to the detectors in the telescope by a cable. High voltage is not available outside the
CRaTER enclosure. When operating the instrument, the chassis must be properly grounded.
Safety Verification Methods
Verify that the chassis is properly grounded.
Status of Verification
Approval
Payload organization
Boston University-CSP
Phase I
Phase II
Phase III
JSC Form 542B
PAYLOAD HAZARD REPORT
Payload
No.
CR 03
Phase
CRaTER Instrument on LRO
Subsystem
Hazard Group
Ground Support Equipment
Ionizing Radiation
0
Date
5/18/06
Hazard Title
Radioactive Source
Applicable Safety Requirement
Hazard Category
Catastrophic
Critical
Description of Hazard
A hand-held radioactive source is required to provide input to the detectors in the telescope in order to test the
CRaTER Instrument. Cobalt 60 (Co60) provides the proper stimulus for CRaTER testing.
Hazard Cause
Cobalt 60 is a radioactive isotope, 5.0 Ci
Hazard Controls
CRaTER test personnel are trained/certified for handling this class of radioactive materials. A radioactive source is
not provided with the flight hardware. For CRaTER testing after delivery, NASA must provide trained/certified
testers and a CO60 source. The radioactive source is not required after integration and testing at GSFC.
Safety Verification Methods
Status of Verification
Approval
Payload organization
Boston University-CSP
Phase I
Phase II
Phase III
JSC Form 542B